Correction: Ecstasy induces reactive oxygen species, kidney water absorption and rhabdomyolysis in normal rats. Effect of N-acetylcysteine and Allopurinol in oxidative stress and muscle fiber damage.

[This corrects the article DOI: 10.1371/journal.pone.0179199.].

Ecstasy induces reactive oxygen species, kidney water absorption and rhabdomyolysis in normal rats. Effect of N-acetylcysteine and Allopurinol in oxidative stress and muscle fiber damage.

BACKGROUND: Ecstasy (Ec) use produces hyperthermia, excessive sweating, intense thirst, an inappropriate antidiuretic hormone secretion (SIADH) and a multisystemic toxicity due to oxidative stress (OS). Intense thirst induces high intake of pure water, which associated with SIADH, usually develops into acute hyponatremia (Hn). As Hn is induced rapidly, experiments to check if Ec acted directly on the Inner Medullary Collecting Ducts (IMCD) of rats were conducted. Rhabdomyolysis and OS were also studied because Ec is known to induce Reactive Oxygen Species (ROS) and tissue damage. To decrease OS, the antioxidant inhibitors N-acetylcysteine (NAC) and Allopurinol (Allo) were used. METHODS: Rats were maintained on a lithium (Li) diet to block the Vasopressin action before Ec innoculation. AQP2 (Aquaporin 2), ENaC (Epitheliun Sodium Channel) and NKCC2 (Sodium, Potassium, 2 Chloride) expression were determined by Western Blot in isolated IMCDs. The TBARS (thiobarbituric acid reactive substances) and GSH (reduced form of Glutathione) were determined in the Ec group (6 rats injected with Ec-10mg/kg), in Ec+NAC groups (NAC 100mg/Kg/bw i.p.) and in Allo+Ec groups (Allo 50mg/Kg/i.p.). RESULTS: Enhanced AQP2 expression revealed that Ec increased water transporter expression, decreased by Li diet, but the expression of the tubular transporters did not change. The Ec, Ec+NAC and Allo+Ec results showed that Ec increased TBARS and decreased GSH, showing evidence of ROS occurrence, which was protected by NAC and Allo. Rhabdomyolysis was only protected by Allo. CONCLUSION: Results showed that Ec induced an increase in AQP2 expression, evidencing another mechanism that might contribute to cause rapid hyponatremia. In addition, they showed that NAC and Allo protected against OS, but only Allo decreased rhabdomyolysis and hyperthermia.

Vitamin D deficiency contributes to vascular damage in sustained ischemic acute kidney injury.

Reductions in renal microvasculature density and increased lymphocyte activity may play critical roles in the progression of chronic kidney disease (CKD) following acute kidney injury (AKI) induced by ischemia/reperfusion injury (IRI). Vitamin D deficiency is associated with tubulointerstitial damage and fibrosis progression following IRI-AKI We evaluated the effect of vitamin D deficiency in sustained IRI-AKI, hypothesizing that such deficiency contributes to the early reduction in renal capillary density or alters the lymphocyte response to IRI Wistar rats were fed vitamin D-free or standard diets for 35 days. On day 28, rats were randomized into four groups: control, vitamin D deficient (VDD), bilateral IRI, and VDD+IRI Indices of renal injury and recovery were evaluated for up to 7 days following the surgical procedures. VDD rats showed reduced capillary density (by cablin staining), even in the absence of renal I/R. In comparison with VDD and IRI rats, VDD+IRI rats manifested a significant exacerbation of capillary rarefaction as well as higher urinary volume, kidney weight/body weight ratio, tissue injury scores, fibroblast-specific protein-1, and alpha-smooth muscle actin. VDD+IRI rats also had higher numbers of infiltrating activated CD4(+) and CD8(+) cells staining for interferon gamma and interleukin-17, with a significant elevation in the Th17/T-regulatory cell ratio. These data suggest that vitamin D deficiency impairs renal repair responses to I/R injury, exacerbates changes in renal capillary density, as well as promoting fibrosis and inflammation, which may contribute to the transition from AKI to CKD.

Hypertonic saline solution for prevention of renal dysfunction in patients with decompensated heart failure.

BACKGROUND: Renal dysfunction is associated with increased mortality in patients with decompensated heart failure. However, interventions targeted to prevention in this setting have been disappointing. We investigated the effects of hypertonic saline solution (HSS) for prevention of renal dysfunction in decompensated heart failure. METHODS: In a double-blind randomized trial, patients with decompensated heart failure were assigned to receive three-day course of 100mL HSS (NaCl 7.5%) twice daily or placebo. Primary end point was an increase in serum creatinine of 0.3mg/dL or more. Main secondary end point was change in biomarkers of renal function, including serum levels of creatinine, cystatin C, neutrophil gelatinase-associated lipocalin-NGAL and the urinary excretion of aquaporin 2 (AQP2), urea transporter (UT-A1), and sodium/hydrogen exchanger 3 (NHE3). RESULTS: Twenty-two patients were assigned to HSS and 12 to placebo. Primary end point occurred in two (10%) patients in HSS group and six (50%) in placebo group (relative risk 0.3; 95% CI 0.09-0.98; P=0.01). Relative to baseline, serum creatinine and cystatin C levels were lower in HSS as compared to placebo (P=0.004 and 0.03, respectively). NGAL level was not statistically different between groups, however the urinary expression of AQP2, UT-A1 and NHE3 was significantly higher in HSS than in placebo. CONCLUSIONS: HSS administration attenuated heart failure-induced kidney dysfunction as indicated by improvement in both glomerular and tubular defects, a finding with important clinical implications. HSS modulated the expression of tubular proteins involved in regulation of water and electrolyte homeostasis.

Carbamazepine can induce kidney water absorption by increasing aquaporin 2 expression.

BACKGROUND: Carbamazepine (Carba) is an anticonvulsant and psychotropic drug used widely for the treatment of intellectual disability and severe pains, but the incidence of hyponatremia is a common related occurrence. This hyponatremia is frequently attributed to a SIADH induced by this drug. It is also known that Carba is used to decrease the urinary volume in Diabetes Insipidus (DI) because it has an antidiuretic effect. Lithium (Li) is one of the most important drugs used to treat bipolar mood disorders. However Li has the undesirable capacity to induce DI. Nowadays, the association of these drugs is used in the treatment of patients with psychiatric and neurological problems. METHODS: In vivo and in vitro (microperfusion) experiments were developed to investigate the effect of Carba in the rat Inner Medullary Collecting Duct (IMCD). RESULTS: The results revealed that Carba was able to stimulate the V2 vasopressin receptor-Protein G complex increasing the (Pf) and water absorption. In vivo studies showed that in rats with lithium-induced DI, Carba decreased the urinary volume and increased the urinary osmolality. AQP2 expression was increased both in normal IMCD incubated with Carba and in IMCD from lithium-induced DI after Carba addition to the diet, when compared with the control. CONCLUSION: These results showed that the hyponatremia observed in patients using this anticonvulsant drug, at least in part, is due to the Carba capacity to increase IMCD's Pf and that the Lithium-Carbamazepine association is beneficial to the patient.

PKC stimulated by glucagon decreases UT-A1 urea transporter expression in rat IMCD.

It is well-known that glucagon increases fractional excretion of urea in rats after a protein intravenous infusion. This effect was investigated by using: (a) in vitro microperfusion technique to measure [(14)C]-urea permeability (Pu x 10(-5)cm/s) in inner medullary collecting ducts (IMCD) from normal rats in the presence of 10(-7)M of glucagon and in the absence of vasopressin and (b) immunoblot techniques to determine urea transporter expression in tubule suspension incubated with the same glucagon concentration. Seven groups of IMCDs (n = 47) were studied. Our results revealed that: (a) glucagon decreased urea reabsorption dose-dependently; (b) the glucagon antagonist des-His(1)-[Glu(9)], blocked the glucagon action but not vasopressin action; (c) the phorbol myristate acetate, decreased urea reabsorption but (d) staurosporin, restored its effect; e) staurosporin decreased glucagon action, and finally, (f) glucagon decreased UT-A1 expression. We can conclude that glucagon reduces UT-A1 expression via a glucagon receptor by stimulating PKC.